Looking in the log of the last community meeting it looks like we should expect Android 7 for Xperia X :

my dream wishes would be for that to happen, together with a decent update of kernel (at least the 4.4 LTS).

The even more far-out wish wouldbe for Jolla to send a team of Ninja assassins to steal the kernel&drivers update that a couple of phones with the exact same chipset as the Jolla 1 have received from Qualcomm, and enable at least a 4.4 Kitkat on the JP-1